Police arrest man in Heathrow alert
Armed police raced to a major security alert at the UK's biggest airport when a man sprinted on to a runway at Heathrow.
The intruder, who was subsequently arrested, was clutching a bag and is thought to have scaled a perimeter fence by the west London airport's northern runway.
The incident caused flight delays and some cancellations.
The breach comes a day before the Queen is due to open the new £4.3bn Terminal 5 building.
Prime Minister Gordon Brown said he was satisfied "everything is now being done to ensure security at Heathrow is intact".
Heathrow workforce sources said the man ran towards a plane but dumped the bag and was quickly tackled by the armed police.
There was a controlled explosion on the bag but police said no explosives were found.
At one stage it was thought that the man might have been protesting ahead of Friday's official opening. But it was later believed the intruder was not a demonstrator.
Buckingham Palace said Friday's visit by the Queen, who will be accompanied by the Duke of Edinburgh, will go ahead as planned.
A Department of Transport spokesman said: "The department is in contact with BAA and if it appears that there were any deficiencies in security then prompt action will be taken."